Heat Transfer to Annular Gas-Liquid Mixtures at Reduced Gravity

HEAT TRANSFER TO ANNULAR GAS-LIQUID MIXTURES AT REDUCED GRAVITY

Abstract

A series of fluid flow and heat transfer experiments was conducted for annular gas-liquid mixtures at reduced gravity aboard NASA's KC-135 aircraft. Air and two liquids, water and 50% aqueous glycerine, were used to produce a range of liquid Reynolds numbers from 1.4 x 10² to 1.4 x 10⁴ in a 25.4-mm-i.d. tube. Pressure drop measurements compare reasonably well with the Lockhart and Martinelli and Wallis correlations. Film thickness measurements compare reasonably well with correlations derived from ground-based vertical annular flow data. The asymptotic Nusselt numbers for 50% glycerine compare well with a turbulent flat-film model, whereas the model overpredicts the water data. For both fluids at higher Reynolds numbers, the asymptotic Nusselt numbers follow a comnion dependence on Reynolds and Prandtl numbers, Nu = AReⁿPr^1/3.

Fore, L.B., Witte, L.C., McQuillen, J.B., Heat Transfer to Annular Gas-Liquid Mixtures at Reduced Gravity, Journal of Thermophysics and Heat Transfer, AIAA, Reston, VA, Vol. 10 (4), October, 1996.